Prior art workers have devised many types of small animal traps involving a water bath in association with some form of balance means which, upon becoming unbalanced by the weight of the animal, will dump the animal into the water bath. U.S. Pat. No. 124,838 teaches an open top vessel partially filled with water. The open top of the vessel is spanned by a bridge, the central portion of which constitutes a bait-containing tilting table. As a small animal crosses the bridge and steps upon the tilting table, he is caused to fall into the water bath. U.S. Pat. No. 141,346 illustrates a somewhat more complex structure comprising a center chamber partially filled with water. A bait container is mounted above the water bath and a series of radially oriented passages lead toward the bait container. The bottom surface of each passage comprises a tiltable trap door which will shift from beneath the animal as he approaches the bait container, causing the animal to fall into the water bath. Means are provided to enable the trap doors to be delicately balanced so that even an insect will trip them.
U.S. Pat. No. 1,635,224 teaches a drum-like vessel, the lower portion of which is filled with water. A pair of diametrically opposed openins is formed in the side wall of the drum above the water bath. A tubular conduit or passage is pivotally mounted within the drum with its ends communicating with the openings in the drum side wall. Means are provided to support bait within and centrally of the tubular passage. As an animal passes through one of the side wall openings and enters the tubular passage, his weight will cause the tubular passage to pivot with the result that the animal will fall into the water bath.
U.S. Pat. No. 2,490,540 illustrates a small animal trap comprising a chamber surmounted by a pivoted and balanced tubular member. A small animal is enticed into the tubular member through the use of bait. The tubular member will become unbalanced by virtue of the animal's weight, discharging the animal into the chamber. The tubular member will thereafter return to its normal horizontal position trapping the animal within the chamber. In a second embodiment, the chamber, itself, may be mounted over a water bath to drown the animal. U.S. Pat. No. 3,778,923 describes an automatic mouse trap device comprising a drowning receptacle having a cover. The cover supports a horizontal runway tube which is tiltable through an elongated slot in the receptacle cover. A rodent passing through the runway tube will cause the tube to become unbalanced and tilt downwardly, discharging the animal into the drowning receptacle. The runway tube will thereafter return to its normal horizontal position.
The references described above are exemplary of those directed to small animal traps utilizing a tilting member which will discharge the animal into a water bath. While effective, such traps are generally characterized by complex construction and the requirement to carefully balance and counterbalance the tilting member. In order for the animal to be trapped, he must pass along the tilting member to the extent that his body weight will cause the member to filt. Sometimes the slightest movement of the tilting member will cause a wary animal to back off and avoid being trapped.
The trap of the present invention is extremely simple in construction, and, as will be described hereinafter, can be configured to be used with a preexisting vessel containing a water bath. The tilting platform of the trap to be described is free floating and does not require delicate balancing and counterbalancing. The animal approaching the tilting platform of the present invention has already assumed a downwardly attitude and the platform will give way from beneath the animal regardless of the animal's weight.